Vol. 68.] 



BEYOZOA FKOM THE LOWER CAEBONIFEEOTJS, 



579^ 



majoritj^ small and inconspicuous. In those parts of the zoaria 

 where the mature region is very narrow, the zooecia often opeiit 



Pig. 12. — Tangential section through the mature region of Stenopora* 

 compacta, showing the suh-polygonal and rounded outlines of the' 

 zooecia (z), small cells, possibly mesopores (s), acanthopores (a),. 

 a7id marked variation in the thickness of the walls.. X ahout 

 20 diameters. 



fh^i 



[The diaphragms should be shown attached to the 

 zooecial walls at all points.] 



obliquely at the surface, and small cells (which may be mesopores) 

 are not seen. 



Horizon and localities. — Bryozoa Band, top of the NematO'- 

 phyllum-minus Sub-zone; Eoman Pell, Weather Hill, and Orton 

 Knott. The best-developed examples are from Weather Hill, but 

 the greatest number are from Boman Pell. 



2t2 



